What Would Swellings Behind Mandible Be?

Hi, I hope you re well. I ve had a swelling in my mandible for years. It s come and gone, painless and movable. But recently my right ear has begun to feel blocked and I feel as though it s bigger. There are also what seem to be two more above this initial one. One behind my ear and the other just below - these are both hard. It s beginning to be slightly achy- though I don t know whether this is because I ve been poking around or not. I m definitely more conscious of it now. The swellings feel about 2 cms each. What could it be?